The Dynamic Gold 105 and the Elevate ate totally different shafts. The DG 105 is a low to mid trajectory shaft and the elevate is built for high trajectory. Even the Elevate Tour is a mid/high trajectory shaft. The VSS in the Elevate is modified Sensicore technology and does dampen vibration and many people like that feel. Strictly from a performance standpoint, you should see a noticeable difference in trajectory when comparing the two.
As far as how long irons last, hard to say. With the exception of lofts getting stronger, many irons from 10 years ago are still relevant, and some older than that are still played. Specs have changed (ie: loft) and have much more of an effect than the technology. Until last year I played our DBM design which is easily a 15 year old design. The only reason I changed was that the lofts were weaker than many modern designs, and I wanted to try our new TS-1’s. I could still play the DBM design, just have adjust club selection due to the slightly weaker lofts. I can’t speak of higher MPF ratings from different manufacturers. From year to year it varies as to what we will see. This year, of the models we measured, we saw 59.4% of new designs fall in the top 3 playability categories and 40.6% fall into the lower three categories. That is an improvement from when the MPF came out back in 2004, where clearly 66% of the clubs on the market at that time were in the bottom three categories of playability, the way we define it. Since then, most years have been a 50 -50 split and some have seen more playable clubs come to market. Whether Ralph and the MPF had anything to do with that, I’ll let others judge. Hopefully, by identifying and calling out the key characteristics of playability, it has had some positive influence. There have been design, material and manufacturing advances that allows us as designers to better control and design so that the mass and dimensional characteristics are more easily positioned and predicted. That being said, the immutable laws of what makes an iron a good design, a playable design, have never changed.
As far a irons “wearing out”, takes a lot of ball beating and a lot of playing to “wear out” irons. If the faces become worn and it is evident that the grooves are wearing, then it is probably time to get a new set. Not sure that was part of your question, but thought I would trow that in there.